While teaching in north-east Arnhem land in the 1970s, Professor Margo Neale would end the school day by letting students flip over their chairs and tables to play them like didjeridus.
"Kids would turn their chairs up at the end of every day, and all of a sudden it would be this orchestra of kids playing down the hollow aluminium legs of the chairs," she said.
"Wherever you went, anything that was hollow that you could put your mouth to, people would be playing it. So it's sort of like an everyday thing, it's not just sacred."
Around four decades later, she is launching the Yidaki: Didjeridu and the Sound of Australia exhibit at the National Museum of Australia where she heads up the Indigenous Knowledges Centre.
The exhibition features yidakis - didjeridus made in Arhem Land, Northern Territory - which have lain dormant for years at the South Australian Museum.
They are at the last leg of their tour, having visited Japan and been shown across Australia.
Globally renowned didjeridu expert Djalu Gurruwiwi explains how the yidakis are made in videos and an interactive display.
Yolngu people tap on stringybark trees and branches to identify ones hollowed out by termites.
After cutting down the tree, they test the sound before deciding whether to completely hollow it out and craft the bark into an instrument.
The sound from each didjeridu is unique.
"There are so many variables. It would be different species have different sounds, the length, the width, whether the end is flared, the moisture content of the wood," said Professor Neale.
"It's an extraordinarily complex instrument to play."
Didjeridu sounds are a more powerful part of the audio-visual exhibit than the objects themselves.
Visitors can even stand on thunderboards to feel the vibrations.
"There is no other sound like it," said Professor Neale. "It is the instrument of Australia."
